Cylinder wall type electromagnetic interference (EMI) filter consisting of spiral flat coil

Abstract

The invention provides a cylinder wall type electromagnetic interference (EMI) filter consisting of a spiral flat coil. The filter comprises an EER magnetic core, and common mode integrated LC modules, a leakage inductance layer and differential mode capacitors which are arranged by taking the EER core as an axis. The common mode integrated LC modules comprises a common mode integrated LC structure I and a common mode integrated LC structure II. The differential mode capacitors comprise a differential mode capacitor I and a differential mode capacitor II. The two common mode integrated LC structures are isolated by the leakage inductance layer. The differential mode capacitor I is arranged at one end of the common mode integrated LC module as the input end of the whole filter, and the differential mode capacitor II is arranged at the other end of the common mode integrated LC module as the output end of the whole filter. The cylinder wall type integrated LC structures are adopted as basic components of the integrated EMI filter provided by the invention, so that high frequency current is uniformly distributed on the spiral flat coil without influencing the performance of the filter; and due to the selection of the EER core, the utilization rate and effective section area of the core are both increased.

Description

technical field [0001] The invention relates to an EMI power supply filter, in particular to a cylinder-wall type EMI filter composed of a spiral flat coil. Background technique [0002] The switching operation of power devices in various power electronic devices causes extremely large voltage or current pulses, which cause severe electromagnetic interference (EMI). At present, there are two main methods for people to solve the problem of electromagnetic interference in power electronics in practical engineering: one is to find out the source of electromagnetic interference in power electronic circuits, and to reduce or eliminate electromagnetic interference by developing new components and designing new circuit topologies. The second is to use electromagnetic interference (EMI) filters to effectively block the transmission path of conducted electromagnetic interference (150 kHz to 30 MHz), which is also the most common and commonly used method to solve electromagnetic inter...

AI Technical Summary

Problems solved by technology

However, the filter also has defects. First, the current distribution at the direct corner is very uneven, which seriously affects the performance of the filter. Second, the utilization rate of the magnetic core is too low, and the effective cross-sectional area of ​​the magnetic core is too small to effectively generate a large enough current. Third, the PCB board forming the planar integrated LC structure is made of ceramic material with high dielectric constant, which is brittle and difficult to install

Images